naphthalene: Dangerious stuff. We lost 2 cats one day when they got it on their coats, they licked it off and it shut down their internal organs and within 12 hours they were dead. That might be the reason that it works to keep the critters out is that it kills them.

Okay, then here are some more to try:
"For years now I have been using whole cloves, not crushed or powder, spread all throughout my 5th wheel camper. This means all around the inside floors, in all storage compartments, drawers, closets, tubs, sinks, even the storage areas for gas tanks and under carriage storage. I have used this method with great results, only one case where one mouse was found in the sink, dead. I do not store my camper in any enclosed storage, always at either a campground, private field, or main driveway with grass and tree’s close by. The lasting smell is much better in the spring time than most of the others I have heard about. When you open the camper in the spring you only have to vacuum up the remaining cloves on the floors, sinks, cabinets, etc"

"I don’t have mice problems but spiders and bees. I found using a dog flea and tick collar cut in strips and put anywhere they can get in works. I replace these every spring and have no problem since using .(5Yrs)"

"We were told to put the Renuzit air fresheners (the one shaped like a cone that you pull up to activate) in every nook and cranny and bin and so far it has worked. course we only picked up one (pregnant) mouse last year parked by a field, and I think a rat in the mountains of Colorado. i caught the mama in a live trap and released her and my cats took care of the 4 adolescents. But the Renuzit alone drove out the rat (or whatever). You can buy copper rodent mesh online and we put it around electrical cord (yes they can), water hose, etc. In fact, if you have an ‘entertainment center’ they can come in through the hole for THAT wiring, too. That is an old wives tale about them leaving for water after the D-Con. They will die in your unit and stink to high heaven. so far Renuzits easiest and best smelling - and so far so good. Will write back if they stop working (must replace when they dry out totally)

PS - we had picked up the mouse before trying the Renuzits. Never picked one up in storage in 5 years, only on a camping trip by the woods. Won’t go without Renuzits again, tho. Ever."

I like the idea of the cloves. Seems like it would leave a pleasant scent vs some of the chemicals available.